Electrical circuits for power factor correction by measurement and removal of overtones and power factor maximization

ABSTRACT

Provided are electrical circuits and methods for power factor correction. An example method includes receiving, by converter, an input voltage at a fundamental frequency and generating an output voltage; generating, based on the output voltage, a first measurement signal; subtracting a first reference signal from the first measurement signal to obtain a first error signal; generating an adaptive current sense signal, generating a reference voltage based on the input voltage, subtracting the reference voltage from the current sense signal thus generating a second measurement signal to control the current measurement; subtracting the second measurement signal from the input voltage to obtain a difference signal, wherein the difference signal is largely minimized by removing overtones of the fundamental frequency; generating, based on the difference signal, a second error signal; using a sum of the second error signal as a first order correction to the first error signal to regulate the converter.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation-in-part of U.S. patentapplication Ser. No. 17/237,973, filed Apr. 22, 2021, now U.S. Pat. No.11,552,554, issued Jan. 10, 2023, which is a continuation of U.S. patentapplication Ser. No. 17/102,035, filed Nov. 23, 2020, now U.S. Pat. No.10,998,815, issued May 4, 2021. All of the aforementioned disclosuresare hereby incorporated by reference herein in their entireties of allpurposes including all references cited therein.

FIELD

The present application relates generally to electrical circuits, andmore specifically, to electrical circuits and methods for power factorcorrection by measurement and removal of overtones.

BACKGROUND

Generators and transformers and electrical loads are connected togetherin power distribution systems that utilize alternating current (AC)power. The generators and transformers generally are designed in such amanner that a current waveform of any load should be sinusoidal and ofthe same shape and phase as the input power voltage supplied by thegenerators and transformers. In power distribution systems, where theload current is sinusoidal and in phase with the input power voltage,the power factor is one. Poorly conditioned loads have power factorsless than 1.

Deviations of the current waveform of the load from the sinusoidal shapeand phase shifts reduce the power factor and may cause losses in thepower distribution systems. These losses may appear as reactive voltagesand currents and harmonic generation and result in increased powerdissipation in the generators, transformers, and so forth. The increasedpower dissipation causes reduction in power efficiency and waste ofenergy and other problems in the power grid. Therefore, there is a needfor removal of the deviations of the waveform of the load current fromthe sinusoidal shape, which appear as overtones of the fundamentalfrequency of the input power voltage, in order to correct and improvethe power factor of the load. Phase errors also need to be removed.

Existing solutions for the removal of the deviations typically involve ahigh-speed current sense loop that operates in a nanosecond time frameand a high-speed current sense. As the output demand or input voltagefor a load current is reduced, which happens during each cycle in the ACinput, the frequency of operation of the current sense loop needs toincrease. However, the frequency is difficult to increase when sensingthe current of light loads. Furthermore, the use of a high-speed currentsense loop is power inefficient because switching losses increase forlower power demands. Additionally, many of the existing solutionsrequire a multiplier circuit that multiplies the feedback value with themeasured rectified AC signal. Using the multiplier circuit results inincreases in the circuit complexity. Another disadvantage of these typesof circuits is that they do not operate at a constant frequency. Thismakes it difficult to filter switching noise and electromagneticinference (EMI). In various embodiments, the technique as describedherein, to reduce input harmonic noise from current from an AC source,may be used to remove harmonic noise when current is driven into an ACsource. The direction of the current flow may change but the method ofharmonic and noise detection and removal remains the same as isdescribed. The same benefits accrue to the usage of this circuit, i.e.reduction of power loss, reduction of switching noise, and thepossibility of simplifying the circuitry. This allows the circuit tosupply current from a DC source to a low impedance AC power grid withhigh efficiency.

SUMMARY

This summary is provided to introduce selected concepts in a simplifiedform that are further described below in the Detailed Description. Thissummary is not intended to identify key features or essential featuresof the claimed subject matter, nor is it necessarily intended to be usedas an aid in determining the scope of the claimed subject matter.

According to an example embodiment of the present disclosure, anelectrical circuit for power factor correction is provided. Theelectrical circuit may include a converter using switches and inductorsto generate a regulated output. The converter can be configured toreceive an input power signal having an input voltage, at a fundamentalfrequency and generate an output power signal having a regulated directcurrent output voltage. The converter is regulated by a first controlsignal. The electrical circuit may include a reference voltage sourceconfigured to provide a reference. The electrical circuit may include afirst measuring circuitry configured to generate, based on the outputvoltage, a first measurement signal. The electrical circuit may includea first operational circuitry configured to subtract the first referencesignal from the first measurement signal, called the first difference,to obtain a first error signal.

The electrical circuit may include an adaptive current sensingcircuitry. The current sense signal is responsive to the input currentand to a second control signal.

The electrical circuit may include a second reference circuitryconfigured to generate, based on the input voltage, a second referencesignal. The second measurement signal may include a sinusoidal orrectified sinusoidal signal. This second measurement signal may have aslowly varying fundamental frequency, the variation of which is muchslower than the fundamental frequency. The electrical circuit mayinclude a second operational circuitry configured to subtract the secondreference signal from the current sense signal, called the seconddifference, to obtain the second control signal by means of a secondoperational circuit. This control signal has a bandwidth considerablysmaller than the frequency of the input power supply. The seconddifference can be minimized by controlling a response of the adaptivesensing circuitry using the second control signal such that thedifference signal includes largely only overtones of the fundamentalfrequency and largely lack a signal corresponding to the fundamentalfrequency. A third operational circuit can generate, based on the seconddifference, a second error signal. This second error signal has abandwidth much wider than the frequency of the input to the power supplyand substantially wider than the first error signal. The electricalcircuit can include a summing circuitry configured to add the seconderror signal and the first error signal to obtain a first controlsignal, and provide the first control signal to control the switches ofthe converter. The first control signal can be used to regulate theoutput of the converter and to increase the power factor,simultaneously.

The converter may include an inductor, a switch, a diode and a gatedriver and control. The switch can be configured to regulate the currentin the inductor. In other embodiments, the converter may include one ormore transformers, switches, diodes, capacitors, gate drivers andcontrol circuitry with the switches being configured to regulatecurrents in transformers or inductors, and capacitors.

The bandwidth of the first error signal can be less than the bandwidthof the second error signal. The adaptive current sensing circuitry mayinclude a voltage variable resistor. The current measurement circuitryin other embodiments may include a resistor, a digitally controlledresistor, a Metal Oxide Silicon Field Effect Transistor (MOSFET), ajunction gated field-effect transistor (JFET), or current transformer.

The second error signal may be treated as a first order perturbation onthe first error signal. The first error signal ought to be able todominate the control loop.

In this embodiment a switch can be controlled by a pulse widthmodulator. The output of the switch can be controlled by regulating aduty cycle of the pulse width modulator without changing the frequencyof turning the switch on and off.

In other embodiments the converter may be of any type, conventionallycalled but not limited to boost, buck-boost, buck, Cuk, resonant,switched capacitor, and even critical conduction mode. The addition ofthe second error signal as a first order correction may be added to thefirst error signal in any of them in order to add power factorcorrection in addition to the primary function of voltage or currentregulation at the output. Embodiments of the present disclosure do notimpact the design of the converter except for adding the second errorsignal to the first error signal and a new current measurement circuit.

In this embodiment the converter consists of a switch, an inductor, adiode, a gate driver, and the control circuitry to control the gatedriver. The converter in other embodiments may include inductors and twoor more switches configured to control a current flowing throughinductors and capacitors. The first error signal can be responsive to acurrent of the output power signal.

According to another example embodiment, an electrical circuit for powerfactor correction (PFC) is provided. The electrical circuit may includea converter previously described. The converter can be configured toreceive an AC input power signal having an input voltage at afundamental frequency and to generate a DC output power signal having anoutput voltage or current. The electrical circuit can include a firstreference signal voltage source. The electrical circuit can include afirst measuring circuitry configured to generate, based on the outputvoltage, a first measurement signal. The electrical circuit may includea first operational circuitry configured to subtract the first referencesignal from the first measurement signal, called the first difference,to obtain a first error signal. The electrical circuit can includecurrent sensing circuitry configured to generate a current sense signalbased on the input current. The electrical circuit may include a secondreference circuitry configured to generate, based on the input voltage,a second reference signal. The second reference signal is a sinusoidalsignal proportional to the rectified input voltage. The differencebetween the current sense signal and the second reference signal iscalled the second difference.

The electrical circuit can include a regulating circuitry configured tocontrol magnitude of the second reference signal with the second controlsignal. The electrical circuit can include a second operationalcircuitry configured to subtract the second measurement signal from thecurrent sense, called the second difference, and create a second controlsignal. The second difference can be minimized by controlling, by theregulating circuitry, a response of the second reference circuitry suchthat the second difference includes mainly overtones of the fundamentalfrequency and largely lacks a signal corresponding to the fundamentalfrequency. A third operational circuitry can be configured to generate,based on the second difference, a second error signal. The bandwidth ofthe second error signal may be substantially greater than the inputfrequency and the bandwidth of the first error signal. The amplitude ofthe second error signal may be less than the amplitude of the firsterror signal. The electrical circuit can include a summing circuitryconfigured to add the second error signal and the first error signal toobtain a first control signal to control the switch, where the summingsignal is used to regulate the switch of the converter. The result is aregulated output of the converter and a maximization of the powerfactor.

According to another example embodiment of the present disclosure, anelectrical circuit power supply with power factor correction isprovided. The electrical circuit power supply may include one or more ofthe following: inductors, capacitors, transformers, switches,amplifiers, comparators, analog-to-digital converters, digital-to-analogconverters, and diodes. The electrical circuit power supply may includea means for controlling the switches with a first control signal inorder to control currents in the inductors, transformers, capacitors,and switches in order to control and regulate an output voltage or anoutput current, and to maximize a power factor of an input current froma sinusoidal voltage source or rectified sinusoidal voltage source at afundamental frequency.

The electrical circuit power supply may include a means of measuring oneof the output voltage or output current and comparing one of the outputvoltage or output current to a first reference signal, and generating afirst error signal responsive to a first difference between the firstreference signal and one of the output voltage or the output current,the first error signal having a first frequency and a first bandwidth.

The electrical circuit power supply may include current measurement ameans for measuring the input current and generating a currentmeasurement signal from the input current.

The electrical circuit power supply may include a means for controllinga gain or magnitude of the current measurement signal generated by thecurrent measuring means.

The electrical circuit power supply may include a means for generating asecond reference signal, the second reference signal comprising asinusoidal reference voltage or a rectified sinusoidal reference voltagederived from the input voltage, and creating a second difference bysubtracting the second reference signal from the current measurementsignal.

The electrical circuit power supply may include a means, a secondoperational circuit, of creating a second control signal proportional tothe second difference, the second difference signal having a secondbandwidth and a second frequency, the second control signal controllingone of a gain or magnitude of the current measurement signal in order tominimize the second difference.

A third operational circuitry can be configured to generate, based onthe second difference, a second error signal. The electrical circuit caninclude a summing circuitry configured to add the second error signaland the first error signal to obtain a first control signal to controlthe switch, where the summing signal is used to regulate the switch ofthe converter. The result is a regulated output of the converter and amaximization of the power factor.

The current measurement means may include a field effect device. Thecurrent measurement may include a Metal Oxide Silicon Field EffectTransistor (MOSFET). The current measurement means may include one ofthe following: a digitally controlled resistor or a digital-to-analogconverter. The current measurement means may utilize a currenttransformer.

Each of the second control signal, first error signal, second error,first control signal, and second difference may be a voltage or adigital signal.

The bandwidth of the second control signal can be substantially lessthan the fundamental frequency while the bandwidth of the second errorsignal can be substantially greater than the fundamental frequency. Thebandwidth of the second error signal can be also substantially greaterthan the bandwidth of the first error signal. A magnitude of the seconderror signal can be substantially less than a magnitude of the firsterror signal.

According to yet another example embodiment of the present disclosure, amethod for the PFC is provided. The method may include receiving, by aconverter controlled via a switch, an input power signal having an inputvoltage at a fundamental frequency. The method may also includegenerating, by the converter, an output power signal having an outputvoltage. The converter is controlled by a first control signal. Themethod may also include, providing, by a reference voltage source, areference signal. The method may also include generating, by a firstmeasuring circuitry, based on the output voltage, a first measurementsignal. The method may also include, subtracting, by a first operationalcircuitry, the first reference signal from the first measurement signalto obtain a first error signal. The difference between the firstreference and the first measurement signal is the first difference.

The method may also include generating, by an adaptive sensing circuitrya current sense signal. The method may also include generating, by asecond reference signal, based on the input voltage, a second referencesignal. The difference is called the second difference. The method mayalso include subtracting, by a second operational circuitry, the secondmeasurement signal from the second reference signal to obtain a secondcontrol signal.

The second difference can be minimized by controlling a response of theadaptive current sensing circuitry by means of the second referencesignal such that the second difference includes substantially onlyovertones of the fundamental frequency and lacks substantially a signalcorresponding to the fundamental frequency. The method may also includegenerating, by a third operational circuitry, based on the seconddifference, a second error signal. The method may also include adding,by a summing circuitry, the second error signal and the first errorsignal to obtain a first control signal. The method may also includeproviding, by the summing circuitry, the first control signal to theswitch, wherein the first control signal is used to regulate the switchof the converter to control the output and to maximize the power factorsimultaneously.

In some aspects, the techniques described herein relate to an electricalcircuit power supply with power factor correction, the electricalcircuit power supply including: a switch-mode converter; a means forcontrolling the switch-mode converter with a first control signal inorder to control currents in the switch-mode converter in order tocontrol and regulate one of an input voltage or an input current, and tomaximize a power factor of an output current into a sinusoidal voltagesource at a fundamental frequency; a means for measuring one of theinput voltage or the input current and comparing one of the inputvoltage or the input current to a first reference signal, and generatinga first error signal responsive to a first difference between the firstreference signal and one of the input voltage or the input current, thefirst error signal having a first error frequency bandwidth; a currentmeasurement means for measuring the output current and generating acurrent measurement signal from the output current; a means forgenerating a second reference signal, the second reference signalincluding a sinusoidal reference voltage or a rectified sinusoidalreference voltage derived from an output or similar reference voltage,and generating a second difference by subtracting the second referencesignal from the current measurement signal; and a means for generating asecond control signal that is proportional to the second difference, thesecond control signal having a control signal frequency bandwidth, thesecond control signal being used to control one of a gain or a magnitudeof the current measurement signal in order to minimize the seconddifference.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the current measurement means is a fieldeffect device.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the current measurement means is a MetalOxide Silicon Field Effect Transistor (MOSFET).

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the current measurement means is one of adigitally controlled resistor or a digital-to-analog converter.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the current measurement means utilizes acurrent transformer.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second control signal is a voltage.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second control signal is a digitalsignal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the first error signal is a voltage.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the first error signal is a digitalsignal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, further including: a means for generating a seconderror signal that is proportional to the second difference, the seconderror signal having a second error frequency bandwidth; and a means forcombining the second error signal with the first error signal togenerate the first control signal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second error signal is a voltage or adigital signal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the first control signal is a voltage.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the first control signal is a digitalsignal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second difference is a voltage.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second difference is a digital signal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the control signal frequency bandwidth isless than the fundamental frequency.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second error frequency bandwidth ofthe second error signal is greater than the fundamental frequency.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second error frequency bandwidth ofthe second error signal is greater than the first error frequencybandwidth of the first error signal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein a maximum magnitude of the second errorsignal is less than a maximum magnitude of the first error signal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply with power factor correction, the electricalcircuit power supply including: a switch-mode converter; a means forcontrolling the switch-mode converter with a first control signal inorder to control currents in the switch-mode converter in order tocontrol and regulate one of an input voltage or an input current, tocontrol a wave form of an output current, and to maximize a powerfactor, the output current being delivered into a sinusoidal voltagesource at a fundamental frequency; a means for measuring one of theinput voltage or the input current and comparing one of the inputvoltage or the input current to a first reference signal, and generatinga first error signal responsive to a first difference between the firstreference signal and one of the input voltage or the input current, thefirst error signal having a first error frequency bandwidth; a currentmeasurement means for measuring the output current and generating acurrent measurement signal from the output current; a means forgenerating a second reference signal including of an alternating current(AC) reference signal proportionately reduced from an output voltage bya means of a controlled voltage divider responsive to a second controlsignal; a first means for controlling a magnitude of a reduction of theoutput voltage and generating a second difference by subtracting the ACreference signal from the current measurement signal; and a means forgenerating the second control signal that is proportional to the seconddifference, the second control signal having a control signal frequencybandwidth, the second control signal driving the first means in order tominimize the second difference.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the current measurement means includes oneof a resistor, a gate field-effect transistor (JFET), a Metal OxideSilicon Field Effect Transistor (MOSFET), or a digitally controlledresistor bridge.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the current measurement means utilizes acurrent transformer.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the controlled voltage divider is aresistor divider with a voltage variable resistor.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the voltage variable resistor is a MOSFET,a field effect device, or a digitally controlled resistor divider.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second control signal is a voltage.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second control signal is a digitalsignal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the first error signal is a voltage.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the first error signal is a digitalsignal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, further including: a means for generating a seconderror signal that is proportional to the second difference, the seconderror signal having a second error frequency bandwidth; and a means forcombining the second error signal with the first error signal togenerate the first control signal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second error signal is a voltage or adigital signal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second difference is a voltage.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second difference is a digital signal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the control signal frequency bandwidth ofthe second control signal is less than the fundamental frequency.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the control signal frequency bandwidth isgreater than the fundamental frequency.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein the second error frequency bandwidth ofthe second error signal is greater than the first error frequencybandwidth of the first error signal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply, wherein a maximum magnitude of the second errorsignal is less than a maximum magnitude of the first error signal.

In some aspects, the techniques described herein relate to an electricalcircuit power supply with power factor correction, the electricalcircuit power supply including: a switch-mode converter; a means forcontrolling the switch-mode converter with a first control signal inorder to control currents in the switch-mode converter in order tocontrol and regulate one of an output voltage or an output current, andto minimize noise and ripple of a DC input current from a DC voltagesource; a means for measuring one of the output voltage or the outputcurrent and comparing one of the output voltage or the output current toa first reference signal, and generating a first error signal responsiveto a first difference between the first reference signal and one of theoutput voltage or the output current, the first error signal having afirst error frequency bandwidth; a current measurement means formeasuring the DC input current and generating a current measurementsignal from the DC input current; a means for generating a secondreference signal, the second DC reference signal, and generating asecond difference by subtracting the second reference signal from thecurrent measurement signal; and a means for generating a second controlsignal that is proportional to the second difference, the second controlsignal having a control signal frequency bandwidth, the second controlsignal being used to control one of a gain or a magnitude of the currentmeasurement signal in order to minimize the second difference.

In some aspects, the techniques described herein relate to an electricalcircuit power supply with power factor correction, the electricalcircuit power supply including: a switch-mode converter; a means forcontrolling the switch-mode converter with a first control signal inorder to control currents in the switch-mode converter in order tocontrol and regulate one of an output voltage or an output current, tocontrol minimize noise and ripple of a DC input current, the DC inputcurrent being received from a DC voltage source; a means for measuringone of the output voltage or the output current and comparing one of theoutput voltage or the output current to a first reference signal, andgenerating a first error signal responsive to a first difference betweenthe first reference signal and one of the output voltage or the outputcurrent, the first error signal having a first error frequencybandwidth; a current measurement means for measuring the DC inputcurrent and generating a current measurement signal from the DC inputcurrent; a means for generating a second reference signal including of aDC current reference signal proportionately reduced from an inputvoltage by a means of a controlled voltage divider responsive to asecond control signal; a first means for controlling a magnitude of areduction of the input voltage and generating a second difference bysubtracting the DC reference signal from the current measurement signal;and a means for generating the second control signal that isproportional to the second difference, the second control signal havinga control signal frequency bandwidth, the second control signal drivingthe first means in order to minimize the second difference.

Other example embodiments of the disclosure and aspects will becomeapparent from the following description taken in conjunction with thefollowing drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example and not limitation in thefigures of the accompanying drawings, in which like references indicatesimilar elements and in which:

FIG. 1 is a high-level block diagram of an example electrical circuitfor power factor correction (PFC), according to some embodiments of thepresent disclosure.

FIG. 2 is a block diagram showing an example electrical circuit forpower factor correction (PFC), according to an example embodiment.

FIG. 3 is a block diagram showing an example electrical circuit forpower factor correction (PFC), according to another example embodiment.

FIG. 4A is a flow chart showing steps of method for PFC, according tosome example embodiments.

FIG. 4B is a flow chart showing additional steps of a method for PFC,according to some example embodiments.

FIG. 5 is a block diagram showing another example electrical circuit forpower factor correction (PFC), according to another example embodiment.

DETAILED DESCRIPTION

The technology disclosed herein relates to electrical circuits andmethods for power factor correction (PFC) by measurement and removal ofovertones or harmonics generated by loads connected to power grids.Embodiments of the present disclosure may allow for improving the PFC inelectrical circuits, which, in turn, may allow for increasing efficiencyof power grids. Furthermore, embodiments of the present disclosure mayresult in better performance of power grids in the best-case conditionsand allow extending operating ranges of power grids and electricalcircuits. Unlike existing technological solutions for the PFC,embodiments of the present disclosure may facilitate more efficient PFCin power grids when alternating current (AC) passes through a range oflow current and low voltage each cycle, as the AC voltage goes throughzero. Specifically, embodiments of the present disclosure may allow forimproving PFC in converters, for example, AC to direct current (DC)converters, and, thereby, increasing power efficiency of the converters.

Embodiments of the present disclosure may solve at least some issuespresented in current solutions for power factor correction. For example,embodiments of the present disclosure can allow operating electricalcircuits for PFC at a largely constant frequency than existing PFCsolutions, which facilitates reducing switching noise andElectro-Magnetic Interference (EMI). Embodiments of the presentdisclosure may also allow removal of the deviations of the waveform ofthe load current from the sinusoidal shape, which appear as overtones orharmonics of the fundamental frequency of the input power voltage inorder to correct and improve the power factor of the load. Embodimentsof the present disclosure may also facilitate removing phase errors inelectrical circuits.

Embodiments of the present disclosure may improve designs of electricalcircuits for PFC by replacing high speed current feedback loops, forexample, a high-speed current sense, with low frequency loops.Embodiments of the present disclosure may allow avoiding the use ofmultiplier circuits in PFC circuits. Embodiments of the presentdisclosure involve current sensing for PFC and utilize removal ofovertones of the sensed current. Therefore, embodiments of the presentdisclosure can be used with any converter having a circuit with anoutput voltage control loop and a voltage control error signal, or anoutput current control loop with a current control signal. Embodiment ofthe present disclosure may allow measuring of how closely the inputcurrent follows the sinusoidal input voltage. Such circuits allowimproving PFC by increasing the operational range of power factorcontrol.

According to an example embodiment of the present disclosure, anelectrical circuit for PFC may include a converter using a switch, aninductor, and a diode. The converter can be configured to receive aninput power signal having an input voltage at a fundamental frequencyand generate a substantially constant output power signal having anoutput voltage. The electrical circuit may include a reference voltagesource configured to provide a reference signal having a referencevoltage. The electrical circuit may include a first measuring circuitryconfigured to generate, based on the output voltage, a first errorsignal 114. The electrical circuit may include a first operationalcircuitry 140 (also called ampifier 140) configured to subtract thefirst reference signal from the first measurement signal (also referredto as the first difference 122), to obtain a first error signal. Theoperation of the first error signal is to largely minimize the value ofthe first difference 122.

The electrical circuit may include adaptive current sense circuitryconfigured to generate, proportional to the input current, a currentsense signal 104. The second measurement method includes a sinusoidalreference signal 102 (also called a sine wave reference signal 102). Theelectrical circuit may include a second operational circuitry 125configured to subtract the sinusoidal reference from the secondmeasurement signal to obtain a second control signal 106. The seconddifference can be minimized by controlling the response of the adaptivesensing circuitry such that the second difference 108 includes mainlyovertones of the fundamental frequency and largely lacks a signalcorresponding to the fundamental frequency. The third operationalcircuitry 130 can generate, based on the second difference, a seconderror signal. The electrical circuit can include a summing unit 150configured to add the second error signal and the first error signal toobtain the first control signal 116 to control the switch. The firstcontrol signal 116 can be used to regulate the switch of the converterin order to regulate the output and to maximize the power factor.

FIG. 1 is a high-level block diagram of an example electrical circuit100 for PFC, according to an example embodiment. The electrical circuit100 can include rectifier and filters 105, adaptive current sense withfeedback 110, converter 115, power output 120, PFC detection amplifier(also called the third operational circuitry 130), summing unit 150, andreference 160. In other embodiments, the converter 115 may includeswitches, inductors, capacitors, diodes, transformers, amplifiers, andother circuitry including digital signal processors.

The rectifier and filters 105 may be configured to convert a power ACelectrical signal, which periodically reverses the direction, into arectified sinusoidal AC electrical supply 107 (current and voltage)having a fundamental frequency. The rectified sinusoidal AC electricalsupply 107 may then provide power to converter 115 via the adaptivecurrent sense with feedback 110.

The converter 115 may receive the rectified sinusoidal AC electricalsupply and convert the rectified sinusoidal AC electrical supply into aDC electrical supply. The switches of converter 115 may includemetal-oxide-semiconductor field-effect transistors (MOSFETs). Anoperational cycle of the converter may involve switching the switch onand off to charge and discharge an inductor. The rectified AC electricalcurrent received by the converter 115 may be distorted from a sinusoidalshape and shifted in phase due to the operation of the switches, diodes,inductors, and control circuitry. This can result in a presence ofovertones of the fundamental frequency, reactive phase shifts, andreduced power factor in the input supply received by the converter 115.

The power output 120 may include a first measuring circuitry configuredto generate, based on the output voltage, an output sample signal 118(also referred to as a first measurement signal). The reference 160 mayinclude a voltage source configured to provide a reference signal 119.The amplifier 140 can be configured to amplify the difference betweenthe reference signal 119 from the output sample signal 118, to obtain afirst error signal 114 by means of the first operational circuitry 140.The difference between the reference signal 119 from the output samplesignal 118 is referred herein to as the first difference 122.

The adaptive current sense with feedback 110 may be configured to sensethe input current received by the converter 115 and generate an inputcurrent sense signal 104). The current sense signal 104 is then providedto PFC detection amplifier also called the second operational circuitry125.

The rectifier and filters 105 may include a second reference circuitconfigured to generate, based on the AC input voltage, an AC sine wavereference signal 102. The AC sine wave reference signal 102 can be arectified sinusoidal signal. The AC rectified sine wave reference signal102 is provided to PFC detection amplifier 125.

PFC detection amplifier 125 can be configured to amplify the differencebetween the sine wave reference signal 102 from the current sense signal104. The second difference 108 is found by subtracting the value of thesine wave reference signal 102 from the current sense signal 104, andthe second difference 108 is presented to the PFC detection amplifier125 which generates the second control signal 106. The second controlsignal 106 causes the adaptive current sense with feedback 110 tominimize the second difference 108. The effect of this minimization islargely due to the removal of the fundamental frequency from the seconddifference 108. The second difference 108 then largely contains onlyharmonics or overtones of the fundamental frequency. The bandwidth ofthe second control signal 106 is much less than the input AC frequency.

The amplifier 130 (also called the third operational circuitry) receivesthe second difference 108. The amplifier 130 can be configured togenerate, based on the second difference 108, a second error signal 112.The summing unit 150 combines the second error signal 112 and the firsterror signal 114 to obtain the first control signal 116 (also referredto as a summing signal) and provide the first control signal 116 tocontrol the converter 115. The first control signal 116 can be used toregulate the converter to regulate operational cycles of the converter115.

The action of the second error signal 112 is to largely remove theharmonics or overtones, and also phase shifts, in the rectifiedsinusoidal AC electrical supply 107 by minimizing the overtones orharmonics in the second difference, while controlling the output voltageor current via the first error signal 114.

The operation of the second control signal 106 is to largely remove thefundamental frequency signal from the second difference 108. Theoperation of the second error signal 112 is to largely remove theremaining harmonics of the fundamental from the second difference 108which removes them from the output.

FIG. 2 is a block diagram showing an example electrical scheme 200 (alsocalled electrical circuit 200) for power factor correction, according toan example embodiment. The electrical scheme 200 can be animplementation of the electrical circuit 100 shown in FIG. 1 .

In electrical scheme 200, the rectifier and filters 105 is carried outby inductors L4 and L5, capacitors C1 and C1A, and diodes D2, D3, D4,and D5. The AC sine wave reference circuit of the rectifier and filters105 is carried out by resistors R88, R89, R92, and R93 and capacitorsC58 and C59. The adaptive current sense with feedback 110 is carried outby the voltage-controlled resistor Gsense, which may be a MOSFET.Capacitors C1 and C1A may be sized to supply energy to the converterwhen the input voltage falls to zero.

The converter 115 is carried out by inductor L1, gate driver X20, MOSFETX12, and diode D1. The power output 120 includes the first measurementcircuitry carried out by capacitor C11 and resistors R6 and R7. Thedevices Rload and C2 are the output load.

PFC detection amplifier (or second operational circuitry) 125 is carriedout by amplifier X26, resistor R46, capacitors C41 and C30, resistorsR74 and R44, and capacitors C46 and C47.

In the electrical scheme 200, the amplifier (third operationalcircuitry) 130 is amplifier X22, the amplifier 140 (or first operationalcircuitry) is amplifier X_ERRAMP, both current mode amplifiers, and thesumming unit 150 is carried out by resistor Rerr and capacitor C40 wherethe output currents are summed.

The rectifier and filters 105 is designed to remove switching noise fromthe supply lines. One of the terminals of the rectifier and filters 105is designated as a circuit ground.

The voltage-controlled resistor Gsense 110 is connected to the circuitground. The voltage-controlled resistor Gsense 110 is designated as theadaptive current sense with feedback. In some embodiments, the variablevoltage resistor Gsense can be implemented by a low resistance MOSFETdevice using the gate as a control node. The voltage on node SENSE 104is the result of the total current flowing in the rectifier and filters105. The electrical circuit 200 is designed to make the current flowingin the rectifier and filters 105 to be sinusoidal and in phase with theinput voltage.

The other terminal of the voltage-controlled resistor Gsense 110 isconnected to the source of the power switching device denoted herein asMOSFET X12, the output filter capacitor C2, and load Rload. Theresistance of the voltage-controlled resistor Gsense 110 may be low,typically tens of milliohms, to measure a current of tens of amperes.

The power switch MOSFET X12 may be a high voltage and high currentdevice. The power switch MOSFET X12 can be driven by a high speed, lowimpedance, gate driver X20. The gate driver in turn can be controlled bya voltage generated by the pulse width modulator x21 to perform pulsewidth modulation of the converter 115. Logic controlling the gate drivemay have an error handling logic which protects the switching powerdevice from error conditions. One of the error conditions is determinedby measuring the power device current to protect the switch X12. Thecycle is ended if current exceeds a threshold. Another condition isdetected at the end of the cycle by determining that the current in theinput inductor L1 has fallen to zero by the end of the cycle also toprotect the switch. The third condition is to make sure that the outputvoltage does not exceed a threshold to protect the load.

The positive side of the rectifier and filters 105 is connected to theinductor L1. The inductor L1 serves as an energy storage device which isused to transfer packets of energy at high frequency through rectifierdiode D1 to the output load Rload and output filter C2. The outputfilter capacitor C2 smooths high frequency energy dumps to create aregulated output voltage to the load Rload. The power switch MOSFET X12causes energy to be stored in the inductor L1 which is then transferredto the load Rload through diode D1.

A resistor divider including resistors R93, R89, and R88 produces avoltage at VDIV 102. The voltage VDIV 102 may be on the order of arounda volt and may be divided down from a source of hundreds of volts. Thevoltage at VDIV 102 may have the form of a rectified sine wave.

The electrical circuit 200 is designed to make the filtered voltage fromSENSE at FSENSE 104 largely equal to the voltage at VDIV 102. If thefiltered voltage SENSE, FSENSE 104, is largely equal to the voltage atVDIV, then the power factor of the electrical circuit 200 is largely 1.This condition is achieved by introducing the amplifier X26. The purposeof the amplifier X26 is to close the loop by controlling the gain of thevoltage-controlled resistor Gsense 110 and drive the voltage on nodeFSENSE 104 as close as possible to the voltage on node VDIV. The resultis that the voltage difference between FSENSE 104 and VDIV 102 haslargely no voltage at the fundamental frequency. The resultantdifference is due to power factor deviations.

The resistors R74 and R44 and capacitors C46 and C47 filter out the highfrequency switching noise in the input voltage and reduce the bandwidthof FSENSE to some multiples of the input frequency to obtain a smoothedsignal presented at the negative input of amplifier X26. The sinusoidalsignal on VDIV 102 is connected to the positive input of the amplifierX26. The output of the amplifier X26 is provided to a low pass filterhaving a few hertz bandwidth. The low pass filter is formed by resistorr46 and capacitor C30 to produce FAMPOUT 106. The filtered output of theamplifier X26 is provided to the control terminal of the voltagevariable resistor Gsense. The functionality of the amplifier X26 and thelow pass filter is to make the voltage on FSENSE 104 as close aspossible to the voltage on VDIV 102 averaged over a number of cycles ofthe AC supply. The voltage difference between VDIV 102 and FSENSE 104 islargely the deviations from the fundamental frequency, that is, theovertones or harmonics from the fundamental frequency and possibly phaseshifts. Thus, the fundamental frequency is largely removed in thevoltage difference between VDIV 102 and FSENSE 104.

Another function of the amplifier X26 is to limit the number ofharmonics admitted to the correction circuitry. This is accomplishedwith the feedback capacitor C41 and the resistor R44. The feedbackcapacitor C41 and the resistor R44 limit the bandwidth of the differencesignal between VDIV 102 and FSENSE 104 largely to a few kilohertz. Thesecond difference 108 between VDIV 102 and FSENSE 104 includes theovertones which are to be removed by the electrical circuit throughamplifier X22 130. Amplifier X22 works to reduce the remainingcomponents of second difference 108, which contain the PFC errors,largely to zero.

The output voltage is controlled by amplifier X_ERRAMP. The dominantpole is created by the output capacitor C2. The output voltage VLOAD isdivided by resistor divider R6 and R7. The divided voltage, FB 118, ispresented to the negative input of amplifier X_ERRAMP. A referencevoltage generated by the reference 160 is provided to the positive inputof the amplifier X_ERRAMP 140. The amplifier X_ERRAMP 140 can be acurrent output amplifier with a current output. The current output ofamplifier X_ERRAMP is introduced to the resistor Rerr to be converted toa voltage. Rerr sums the output currents of amplifier X22 and X_ERRAMPand converts the currents to a voltage, the first control signal 116.The error voltage on node ERR is presented to the circuitry X21. Thecircuitry X21 converts error voltage to duty factor of the MOSFET X12.

In some error conditions, if the inductor L1 current does not drop tozero before the end of the cycle of the converter 115, a new cycle isnot initiated. If the current in the inductor L1 exceeds a limit, theMOSFET X12 is turned off to protect the MOSFET switch. If the outputvoltage exceeds a limit, the cycle of the converter 115 is turned off toprotect the load.

Overtone removal occurs through the amplifier X22 130. The output ofamplifier X22 130 is summed with the output of the amplifier X_ERRAMP140. The amplifier X22 130 forces the current in GSENSE to be largelysinusoidal by removing the residual, non-sinusoidal, components in theload current. This is accomplished by minimizing the difference betweenFSENSE 104 and VDIV 102.

In some embodiments, the inductor L1, can be replaced by a transformer,such that the magnetic energy is transferred to the output via asecondary winding. The electrical circuit with the transformer can besimilar to the electrical circuit 200 except for using another form offeedback, such as an optocoupler, to regulate the output voltage. Tooperate, the output of the optocoupler needs to be summed with theoutput of the amplifier X22 130.

For an AC to DC converter to work, the output bandwidth is required tobe approximately equal to or less than the frequency of the input ACsignal, otherwise the output would substantially vary as the inputvoltage. For the overtone removal to work, the output current fromamplifier X22 needs to have a bandwidth significantly higher thanseveral multiples of the input voltage frequency. Thus, the pole ofcapacitor C40 and resistor Rerr needs to be substantially greater thanthe unity gain bandwidth of the dominant pole of capacitor C2 of themain error loop.

The electrical circuit 200 can be adapted to work on a three-phaseinput, keeping the phases in balance. In this case the input currentneeds to be measured by a different method, other than a resistor in theground line, because the ground current of all three phases flows in theresistor. This limitation can be overcome by use of current transformersin the three legs of the three-phase bridge rectifier and the use ofmatched harmonic amplifiers coupled with matched error amplifiers. Thecurrent in each of the three legs might be leveled, further improvingpower factor on the higher level of the three-phase system.

FIG. 3 is a block diagram showing an example electrical circuit 300(also called electrical scheme 300) for power factor correction,according to another example embodiment. The electrical scheme 300 canbe an implementation of the electrical circuit 100 shown in FIG. 1 . Theelectrical scheme 300 is a modification of the electrical scheme 200.The difference between the electrical circuit 200 is that the adaptivecurrent sense with feedback 110 (variable voltage resistor Gsense) inthe electrical circuit 300 is replaced with a fixed resistor Rsense andthe resistor R88 is replaced with variable voltage resistor Gres. Thegeneral operation is similar except now FAMPOUT 106 is connected toGres. Also, the inputs to the amplifier X26 are reversed.

In some embodiments of the present technology, as shown in FIG. 2 if thesupplies are replaced by DC power supplies, the circuit becomes a DC toDC converter. A DC to DC converter changes voltage levels between inputand output. The circuit as described, with no other modification, willoperate to remove noise and AC ripple from the input current. Thisripple and noise may be introduced by an AC load, like a DC to ACconverter, connected to the output of the DC to DC converter. Thiscircuit has the advantage of keeping the input current constant. Thismay be an advantage for some input supplies such as battery and solarpanels that may have better performance with low output current ripple.

FIG. 4A and FIG. 4B are a flow chart of method 400 for power factorcorrection, according to some example embodiments. The method 400 can beimplemented, for example, by the electrical circuit 200 shown in FIG. 2.

In block 405, the method 400 may commence with receiving, by a convertercontrolled via a switch, an input power signal having an input voltageat a fundamental frequency. The switch is configured to regulate acurrent in the inductor or transformer responsive to a first controlsignal. In other embodiments the converter may include one or moreinductors or one or more one or more transformers, and one or moreswitches.

In block 410, the method 400 may include generating, by the converter,an output power signal having an output voltage. The switch of theconverter can be controlled by a pulse width modulator. The output ofthe switch can be controlled by regulating a duty cycle of the pulsewidth modulator and without changing a frequency of turning the switchon and off.

In block 415, the method 400 may include providing, by a referencevoltage source, a reference signal.

In block 420, the method 400 may include generating, by a firstmeasuring circuitry, based on the output voltage, a first measurementsignal.

In block 425, the method 400 may include subtracting, by a firstoperational circuitry, the first reference signal from the firstmeasurement signal to obtain a first error signal. The first errorsignal is responsive to the output of the converter.

In block 430, the method 400 may include generating, by an adaptivesensing circuitry, based on the input voltage, a current sense signalproportional to the input current. The adaptive sensing circuitry mayinclude a voltage variable resistor. This resistor may be a MOSFET,JFET, or a digitally controlled resistor.

In block 435, the method 400 may include generating, by a secondmeasurement circuitry, based on the input voltage, a second referencesignal. The second reference signal is a rectified sinusoidal signal.The second measurement circuitry may include a voltage variableresistor. The second measurement circuitry may include a currenttransformer in some embodiments.

In block 440, the method 400 may include subtracting, by a secondoperational circuitry, the second reference signal from the currentsense signal to obtain a second difference signal. The difference signalis minimized by controlling a response of the adaptive sensing circuitryutilizing a voltage variable resistor to take the average of thedifference signal. The difference signal then includes substantiallyonly overtones of the fundamental frequency and lacks substantially asignal corresponding to the fundamental frequency.

In block 445, the method 400 may include generating, by a thirdoperational circuitry, based on the second difference signal, a seconderror signal. A bandwidth of the first error signal can be less than abandwidth of the second error signal. The maximum amplitude of thesecond error signal is nominally less than the maximum amplitude of thefirst error signal.

In block 450, the method 400 may include adding, by a summing circuitry,the second error signal and the first error signal to obtain a summingsignal (the first control signal); and

In block 455, the method 400 may include providing, by the summingcircuitry, the summing signal to the switch, wherein the summing signalis used to regulate the switch of the converter, in order to regulatethe output voltage and to substantially maximize the power factorsimultaneously.

FIG. 5 is a block diagram showing another example electrical circuit forpower factor correction (PFC), according to another example embodiment.FIG. 5 is a block diagram showing an example electrical scheme 500 forpower factor correction, according to an example embodiment. Theelectrical scheme 500 can be an implementation of the electrical circuit100 shown in FIG. 1 .

In some embodiments, the same circuits and principles of FIG. 1 , FIG. 2and FIG. 3 are used not to power factor correct the input current into aDC switch-mode regulator. Rather they are used to power factor correctthe output current of a DC to AC converter. This means removing theharmonics and phase shifts of the output current. So instead of sensingthe input AC voltage and input current, the output AC voltage andcurrent are measured and the voltage Vdiff is used to correct the phaseand remove harmonics from the output current instead of the inputcurrent.

It should be noted that both the parental patent applications U.S.patent application Ser. No. 17/237,973, filed Apr. 22, 2021, which is acontinuation of U.S. patent application Ser. No. 17/102,035, filed Nov.23, 2020 are used to interface DC loads and sources with low impedanceAC loads and sources in various embodiments. The voltage of the AC loador source is determined by the external environment such as a generator.The circuit is only controlling currents into, or out of, azero-impedance source or sink. For example, referring to FIG. 5 andXAmp1 and XAmp2 are the equivalent of Amp1 and Amp2 of previous figures.For example, the voltage on the output is measured by a full waverectifier, here through a transformer K3 to give the interior circuitsome isolation from the power circuit. The value VDIV is divided down tobe a small fraction of the output voltage.

In some embodiments, the output is, in this example, a pulse widthmodulated switch-mode converter driving current into the externalcircuit through transformer K2. This is only one of a large number ofpossible switch-mode regulator circuits which can be used with thismethod. The sign of the external wave determines which primary windingof K2 is used. The current in the primary windings of K2 areproportional to the current in the output winding. This current ispassed through a variable resistor, here a MOSFET, M_VAR. The signal,VDIFF=Vdiv−fsense, is amplified and combined with the signal regulatingthe output current into the external AC circuit from a battery or solarcells. The difference voltage, VDIFF, contains the harmonic content ofthe current signal.

In various embodiments, that control voltage could be proportional tosome average DC current output from the DC source as it is in thisconcept. It could be relative to some voltage like the battery chargevoltage or battery temperature. The output of that error amplifier, herecalled ERROR AMPLIFIER, is combined with the output of the HARMONICSAMPLIFIER to form the composite signal to control both the nominal DCsource condition, like average current, and the signal used to removethe non-sinusoidal components of the output current. The error signalwill be used to control the switching regulator to control the currentinjected into the AC line by the transformer K2. This injected currentwill be power factor corrected. For example, there is a switch SW1indicated here. It is to show that the circuit will work without theaddition of the power factor correction, albeit with poor power factor.

In some embodiments, in this representative circuit the error signal ismultiplied by a sinusoidal voltage derived from the output voltage, asshown in the schematic as PRODUCT FUNCTION. This is included to make theoutput current closer to sinusoidal without the use of the power factorcorrection circuit. The power factor of this circuit alone will be poorbut better than with no multiplication. This multiplication is done in amillisecond time frame, on the order of the frequency of the AC outputvoltage wave form. In this example the switch-mode current is steeredthrough the primary winding of transformer K2 to produce an ACsinusoidal current injected into the AC voltage output. There are manypossible ways to implement the AC current injection in addition to thisexample. This is simply representative. There are many other methods forinterfacing the DC source with an AC load that do not require atransformer. These methods generally work with switched capacitors. Thisgeneral method of power factor correction will work with these methodsin various embodiments.

In various embodiments, the external AC signal is sampled by transformerK3. That sample is used to drive the switch-mode regulator as a 1^(st)order sinusoidal reference wave form. The output of the HARMONICSAMPLIFIER, or DIFFAMP, removes the remaining non-sinusoidal componentsof that wave by negative feedback.

In some embodiments, it is proposed that the power factor of thiscircuit is limited only by the gain of the amplifiers and should be veryclose to 1. The simulations of the parental patent applications U.S.patent application Ser. No. 17/237,973 filed Apr. 22, 2021, which is acontinuation of U.S. patent application Ser. No. 17/102,035, filed Nov.23, 2020, confirm this projection. For example, the result is that theclaims of parental patent applications U.S. patent application Ser. No.17/237,973, filed Apr. 22, 2021, which is a continuation of U.S. patentapplication Ser. No. 17/102,035, filed Nov. 23, 2020 are identical tothe claims of the new extension except for the direction of informationflow. Inputs and outputs are changed. In the first case current iswithdrawn from a low impedance AC voltage wave form. In the second casecurrent is injected into a low impedance AC wave form. Again, it must beemphasized, that this invention is an add-on to other solutions to theproblem of injecting current from a battery into an AC circuit. Theadd-ons are Xamp1, Xamp2 and DIFFAMP. The switch in FIG. 5 emphasizesthis point.

A Non-Patent Literature document in the journal Transactions on PowerElectronics by Yon Zhang, et. al, titled “Capacitors Voltage RippleComplementary Control on Three-Level Boost Fed Single-Phase VSI WithEnhanced Power Decoupling Capability,” IEEE Trans. on Power Electronics,Vol. 36, No. 12, pp. 14220-14236, December 2021 is incorporated byreference for all purposes. This Non-Patent Literature document is onthe subject of injecting current from a battery to an AC line. ThisNon-Patent Literature document deals with a method of using capacitorsto inject current into the AC source rather than a transformer as usedin the present disclosure. This Non-Patent Literature document does notdisclose the present technology, although it would benefit with thebolt-on addition of this technique in several ways.

The present technology is described above with reference to exampleembodiments. Therefore, other variations upon the example embodimentsare intended to be covered by the present disclosure.

What is claimed is:
 1. An electrical circuit power supply with powerfactor correction, the electrical circuit power supply comprising: aswitch-mode converter; a means for controlling the switch-mode converterwith a first control signal in order to control currents in theswitch-mode converter in order to control and regulate one of an inputvoltage or an input current, and to maximize a power factor of an outputcurrent into a sinusoidal voltage source at a fundamental frequency; ameans for measuring one of the input voltage or the input current andcomparing one of the input voltage or the input current to a firstreference signal, and generating a first error signal responsive to afirst difference between the first reference signal and one of the inputvoltage or the input current, the first error signal having a firsterror frequency bandwidth; a current measurement means for measuring theoutput current and generating a current measurement signal from theoutput current; a means for generating a second reference signal, thesecond reference signal comprising a sinusoidal reference voltage or arectified sinusoidal reference voltage derived from an output referencevoltage, and generating a second difference by subtracting the secondreference signal from the current measurement signal; and a means forgenerating a second control signal that is proportional to the seconddifference, the second control signal having a control signal frequencybandwidth, the second control signal being used to control one of a gainor a magnitude of the current measurement signal in order to minimizethe second difference.
 2. The electrical circuit power supply of claim1, wherein the current measurement means is a field effect device. 3.The electrical circuit power supply of claim 1, wherein the currentmeasurement means is a Metal Oxide Silicon Field Effect Transistor(MOSFET).
 4. The electrical circuit power supply of claim 1, wherein thecurrent measurement means is one of a digitally controlled resistor or adigital-to-analog converter.
 5. The electrical circuit power supply ofclaim 1, wherein the current measurement means utilizes a currenttransformer.
 6. The electrical circuit power supply of claim 1, whereinthe second control signal is a voltage.
 7. The electrical circuit powersupply of claim 1, wherein the second control signal is a digitalsignal.
 8. The electrical circuit power supply of claim 1, wherein thefirst error signal is a voltage.
 9. The electrical circuit power supplyof claim 1, wherein the first error signal is a digital signal.
 10. Theelectrical circuit power supply of claim 1, further comprising: a meansfor generating a second error signal that is proportional to the seconddifference, the second error signal having a second error frequencybandwidth; and a means for combining the second error signal with thefirst error signal to generate the first control signal.
 11. Theelectrical circuit power supply of claim 10, wherein the second errorsignal is a voltage or a digital signal.
 12. The electrical circuitpower supply of claim 10, wherein the second error frequency bandwidthof the second error signal is greater than the fundamental frequency.13. The electrical circuit power supply of claim 10, wherein the seconderror frequency bandwidth of the second error signal is greater than thefirst error frequency bandwidth of the first error signal.
 14. Theelectrical circuit power supply of claim 10, wherein a maximum magnitudeof the second error signal is less than a maximum magnitude of the firsterror signal.
 15. The electrical circuit power supply of claim 1,wherein the first control signal is a voltage.
 16. The electricalcircuit power supply of claim 1, wherein the first control signal is adigital signal.
 17. The electrical circuit power supply of claim 1,wherein the second difference is a voltage.
 18. The electrical circuitpower supply of claim 1, wherein the second difference is a digitalsignal.
 19. The electrical circuit power supply of claim 1, wherein thecontrol signal frequency bandwidth is less than the fundamentalfrequency.
 20. An electrical circuit power supply with power factorcorrection, the electrical circuit power supply comprising: aswitch-mode converter; a means for controlling the switch-mode converterwith a first control signal in order to control currents in theswitch-mode converter in order to control and regulate one of an inputvoltage or an input current, to control a wave form of an outputcurrent, and to maximize a power factor, the output current beingdelivered into a sinusoidal voltage source at a fundamental frequency; ameans for measuring one of the input voltage or the input current andcomparing one of the input voltage or the input current to a firstreference signal, and generating a first error signal responsive to afirst difference between the first reference signal and one of the inputvoltage or the input current, the first error signal having a firsterror frequency bandwidth; a current measurement means for measuring theoutput current and generating a current measurement signal from theoutput current; a means for generating a second reference signalcomprising of an alternating current (AC) reference signalproportionately reduced from an output voltage by a means of acontrolled voltage divider responsive to a second control signal; afirst means for controlling a magnitude of a reduction of the outputvoltage and generating a second difference by subtracting the ACreference signal from the current measurement signal; and a means forgenerating the second control signal that is proportional to the seconddifference, the second control signal having a control signal frequencybandwidth, the second control signal driving the first means forcontrolling the magnitude in order to minimize the second difference.21. The electrical circuit power supply of claim 20, wherein the currentmeasurement means includes one of a resistor, a gate field-effecttransistor (JFET), a Metal Oxide Silicon Field Effect Transistor(MOSFET), or a digitally controlled resistor bridge.
 22. The electricalcircuit power supply of claim 20, wherein the current measurement meansutilizes a current transformer.
 23. The electrical circuit power supplyof claim 20, wherein the controlled voltage divider is a resistordivider with a voltage variable resistor.
 24. The electrical circuitpower supply of claim 23, wherein the voltage variable resistor is aMOSFET, a field effect device, or a digitally controlled resistordivider.
 25. The electrical circuit power supply of claim 20, whereinthe second control signal is a voltage.
 26. The electrical circuit powersupply of claim 20, wherein the second control signal is a digitalsignal.
 27. The electrical circuit power supply of claim 20, wherein thefirst error signal is a voltage.
 28. The electrical circuit power supplyof claim 20, wherein the first error signal is a digital signal.
 29. Theelectrical circuit power supply of claim 20, further comprising: a meansfor generating a second error signal that is proportional to the seconddifference, the second error signal having a second error frequencybandwidth; and a means for combining the second error signal with thefirst error signal to generate the first control signal.
 30. Theelectrical circuit power supply of claim 29, wherein the second errorsignal is a voltage or a digital signal.
 31. The electrical circuitpower supply of claim 29, wherein the second error frequency bandwidthof the second error signal is greater than the first error frequencybandwidth of the first error signal.
 32. The electrical circuit powersupply of claim 29, wherein a maximum magnitude of the second errorsignal is less than a maximum magnitude of the first error signal. 33.The electrical circuit power supply of claim 20, wherein the seconddifference is a voltage.
 34. The electrical circuit power supply ofclaim 20, wherein the second difference is a digital signal.
 35. Theelectrical circuit power supply of claim 20, wherein the control signalfrequency bandwidth of the second control signal is less than thefundamental frequency.
 36. The electrical circuit power supply of claim20, wherein the control signal frequency bandwidth is greater than thefundamental frequency.
 37. An electrical circuit power supply with powerfactor correction, the electrical circuit power supply comprising: aswitch-mode converter; a means for controlling the switch-mode converterwith a first control signal in order to control currents in theswitch-mode converter in order to control and regulate one of an outputvoltage or an output current, and to minimize noise and ripple of aninput current received from a DC voltage source; a means for measuringone of the output voltage or the output current and comparing one of theoutput voltage or the output current to a first reference signal, andgenerating a first error signal responsive to a first difference betweenthe first reference signal and one of the output voltage or the outputcurrent, the first error signal having a first error frequencybandwidth; a current measurement means for measuring the input currentand generating a current measurement signal from the input current; ameans for generating a second reference signal, and generating a seconddifference by subtracting the second reference signal from the currentmeasurement signal; and a means for generating a second control signalthat is proportional to the second difference, the second control signalhaving a control signal frequency bandwidth, the second control signalbeing used to control one of a gain or a magnitude of the currentmeasurement signal in order to minimize the second difference.
 38. Theelectrical circuit power supply of claim 37, further comprising: a meansfor generating a second error signal that is proportional to the seconddifference, the second error signal having a second error frequencybandwidth; and a means for combining the second error signal with thefirst error signal to generate the first control signal.
 39. Theelectrical circuit power supply of claim 37, wherein at least one of:the first control signal, the first reference signal, the first errorsignal, the current measurement signal, and the second reference signalis a digital signal.
 40. An electrical circuit power supply with powerfactor correction, the electrical circuit power supply comprising: aswitch-mode converter; a means for controlling the switch-mode converterwith a first control signal in order to control currents in theswitch-mode converter in order to control and regulate one of an outputvoltage or an output current, to minimize noise and ripple of a DC inputcurrent, the DC input current being received from a DC voltage source; ameans for measuring one of the output voltage or the output current andcomparing one of the output voltage or the output current to a firstreference signal, and generating a first error signal responsive to afirst difference between the first reference signal and one of theoutput voltage or the output current, the first error signal having afirst error frequency bandwidth; a current measurement means formeasuring the DC input current and generating a current measurementsignal from the DC input current; a means for generating a secondreference signal comprising of a DC current reference signalproportionately reduced from an input voltage by a means of a controlledvoltage divider responsive to a second control signal; a first means forcontrolling a magnitude of a reduction of the input voltage andgenerating a second difference by subtracting the DC current referencesignal from the current measurement signal; and a means for generatingthe second control signal that is proportional to the second difference,the second control signal having a control signal frequency bandwidth,the second control signal driving the first means for controlling themagnitude in order to minimize the second difference.
 41. The electricalcircuit power supply of claim 40, further comprising: a means forgenerating a second error signal that is proportional to the seconddifference, the second error signal having a second error frequencybandwidth; and a means for combining the second error signal with thefirst error signal to generate the first control signal.
 42. Theelectrical circuit power supply of claim 40, wherein at least one of:the first control signal, the first reference signal, the first errorsignal, the current measurement signal, and the second reference signalis a digital signal.